In A Heartbeat
by JustOneLittleProblem
Summary: Rose Tyler's first big mistake was to be born during the Last Great Time War. Her second was to join her childhood best friend in crewing a gunship in a Dalek infested area. When the Doctor shows up, choices must be made, and consequences faced.
1. Chapter 1

When Rose Tyler was six years old, her mother gave her the ruby ring with the stylised heart shaped stone that would one day lead her to her soulmate. There was only one thing wrong with the ring.

It had two heart shaped rubies instead of one. Rose's blood chilled. Even at her age, she knew exactly what that meant. Her soulmate was a Time Lord, the destroyers of countless planets in the Kasterborous constellation. Time Lords were evil, everyone knew that. Rose tipped her chin up as she gazed at her mother. But her voice shook when she spoke. "Mum, why is my soulmate a Time Lord? They're twisted. Wrong. They're as bad as the Daleks."

Jackie Tyler knelt down, gathering Rose into a gentle hug. "They're not evil," Jackie stated quietly.

"How do you know?" Rose asked in a muffled voice; her face was buried in her mother's shoulder.

"They're people, just like us. Driven by love, loss, fear, hatred. The same things that motivate us. Some view us as collateral damage, necessary to save the universe, while others see us as deserving of life as they are. Does that make sense?" Rose nodded, reassured.

She stepped back, staring at the ring in fascination. Rose knew that the details of the ring told something about the person they were crafted to represent. Curlicues of blued metal, and curious little geodes smaller than a greyhound beetle that resembled the inside of a crystalline star. Rose shook her head, and smiled. She couldn't wait for the future.

Theta Sigma, one day to be the Doctor, sat on the roof of the Time Academy, slowly spinning the ring on his left hand. Theta had memorised the ornate golden band about a hundred years ago.

Carved wolves made of gold prowled next to the singular heart-stone, whilst gemstone roses bloomed. Theta didn't have anything better to do, so he daydreamed about meeting his soulmate for the first time. However, the reality didn't live up to the expectation. At all.

When Rose was eight years old, her comfortable world was shattered for the first time. Rose awoke in the middle of the night to Jackie dragging her out of bed.

Her mother took her, bolting into the main plaza of their little town. Screaming shattered the night, with noxious black smoke already rising from the horizon. Quakes rocked the ground, cracks already zigzagging.

Like sinister shooting stars, Dalek ships arched across the upper atmosphere. A small gunship awaited them, people already climbing in. They piled inside, the doors of the ship closed, and it arrowed into the sky. Rose would never forget the lonely beauty of her home planet, hanging alone in star-studded velvety darkness.

Nor would she ever forget the dusty greenish yellow continents dissolving a second before her only home blew apart into a million fragments. Rose closed her eyes, still hearing the screams of her friends and neighbours. Those screams would follow her into adulthood and beyond.

Cass Corde stared at Rose in exasperation, wondering why the heck they'd put her best friend on this gunship. "The heroes died first, Rose. Makes me wonder where they dug you up."

Rose grinned weakly at her. "A backwater farming planet. Besides, cowards die too. You ought to be careful."

The little ship bucked, groaning with the stresses of G-force and its own damage. Cass stepped up to the controls of the transmat beam, ready to beam Rose back to safety. Rose just tilted her chin up, glaring mulishly at Cass. "No. It's not happening."

They glared at each other for a long moment, then Cass backed down. She was unlikely to be able to stuff Rose into the transmat, _and_ operate the controls. "Might as well set the distress signal. Maybe there's someone out there who can save our sorry hides."

Rose's smile was bright, her eyes sad. "Maybe."

They both knew that only a TARDIS or a Dalek saucer would be able to stop them from hitting the surface of Karn, and that was a dubious kind of salvation anyway.

The Doctor groaned, flopping into the overstuffed green armchair that had been his since the middle of his seventh incarnation. The Doctor tried not to think, tried not to feel. But the fact remained that the Time War was getting worse.

Soon its full fury would crash down upon the universe, and everything would be lost to madness. Some said that it was the Last Great Time War, because everything would burn in its wake, Dalek, Time Lord, and human alike.

The Doctor glanced down at the intricate golden ring on his left hand, and sighed. Most Time Lords found their soulmates by the age of two hundred or so. He was well past two thousand years of age, and still hadn't met them. Maybe his soulmate had died.

Goodness knew enough other people had died in this war. Humanity had grown to touch every star in the sky, and now it would all- the Doctor stuffed the thought down viciously. He cast about for a distraction.

The distraction the Doctor was seeking arrived a moment later with a series of quiet bleeps. A distress signal. Far too many of them, these days. The Doctor moved swiftly across the room, and set the coordinates. Five minutes later, he strode out of the newly materialised TARDIS, into a storage room filled with supply crates.

The craft was jerking and wallowing wildly, and the Doctor knew from the data that the TARDIS had fed him, it was going to crash on Karn. Time to evacuate as many people as possible. Except for the fact, the Doctor realised, that everyone seemed to have left the ship.

The Doctor heard voices, and turned a corner. Two young women hunched over a computer interface, arguing with the recalcitrant AI. Neither of them seemed to notice him. At that moment, the ring on the Doctor's left hand began to beat with a single, human heartbeat.

"Help us, please. Can anyone hear us?" Desperation and the need for survival were beginning to set in, and Cass heard her anxious voice in a detached sort of way. But no god answered. Not even another ship.

Only the tinny voice of the computer's governing intelligence. "Please state the nature of your ailment or injury."

Rose, in a display of temper, barely missed punching the display. "Neither of us is injured, damn it!"

If computers could sound exasperated, this one did. "Providing a clear statement of your symptoms can help us provide the medical practitioner most suitable for your needs."

Cass and Rose both groaned, and Rose really did punch the readout this time. Sparks flew, and Rose shook out her fist. They looked at each other, and abruptly Rose smiled. "When you said best friends to the end, I didn't quite imagine it ending quite like this. No one to help. No lives to save. Just… this."

The despair in Rose's eyes and voice nearly broke Cass. Stubborn, fiery, compassionate, that was Rose. Not this. "We did what we could," Cass reminded her.

Instead of replying, Rose gasped and whipped around, fumbling for the fingerless gloves she always wore. Dimly Cass saw Rose rip off the left one, but all her attention was on the man standing in the doorway. He was only slightly taller than Rose or Cass herself, with piercing blue eyes, shorn chestnut curls, and a battle worn black leather jacket.

Cass's spine sagged with an inexplicable sense of safety. What really registered, though, was the red cord binding him to Rose. The Red String of Fate. He was Rose's soulmate. He and Rose seemed to be having an intense silent discussion. Probably telepathy. Finally he broke eye contact with Rose. "Hello Cass, I'm the Doctor. Pleasure to meet you."

The sense of safety he brought mostly vanished in a single heartbeat as Cass processed what that title meant. Terror, instilled since infancy, screamed up her spine, mixing with rage and betrayal in the pit of her stomach. This was no kind of rescue at all. " **Get out**." Cass said, sounding more calm than she felt.

The smile faded from the Doctor's face, replaced by serene calm. "No. I will not leave you or Rose to your deaths."

Cass was about to retort that if one of _them_ died, then that was worth their lives, but something stopped her. Soulmates were each other's mirror images, with complementary differences, but at the core they were the same. Rose wasn't evil. So maybe, just maybe this Time Lord was different. Although if she weren't kidding herself, it was the pleading look Rose was giving her that changed her mind.

Cass couldn't send her childhood best friend to her death. Not when there was a chance to save all of them. In the instant Cass made her decision, something shifted above human perception. The timelines altered, flowing like quicksilver into their new pathways. Cass gained a future, and wars were won and lost.

The Doctor smiled gently at her. "I thought so." There was no mockery in his words. Then the Doctor held out a hand to each woman, grinning. "Run for your lives!" They did.


	2. Chapter 2

The three of them skidded to a halt in front of the TARDIS, and the Doctor began frenetically unlocking the door. Cass squinted at the blocky, unremarkable blue box. "What is she pretending to be, anyway?"

The Doctor spit out the TARDIS key, saying absently, "She's supposed to be a police box. From Earth."

Cass raised a sceptical eyebrow. Earth was a myth. The Doctor was either oblivious to the insult in Cass's expression, or wisely chose to ignore it.

Rose grinned happily at them, gesturing at the 'police box'. "I like her."

The door creaked open, and they stepped inside. Cass aimed a teasing grin at Rose. "Of course you do, o girl of the fluorescent pink denim jacket."

Rose rolled her eyes. "I thought we agreed never to mention that again."

They followed the Doctor, their eyes gradually adjusting to the dimly lighted space. By the time they could see again, Cass's jaw dropped. The interior of the TARDIS what not at all what she expected. Then again, Cass wasn't sure what she expected.

Something sinister, reflecting the blood-soaked nature she'd believed all Time Lords possessed. This wasn't even close. Warm wood lockers lined the back of an immense room, with various odds and ends arranged around the edges, including a library, a small sitting room, and a fish pond. Cass highly suspected that the fish pond's only purpose was to dunk the Doctor whenever the ship got annoyed.

Doors led away, stretching into endless, brilliant white corridors. Cass glanced toward the centre of the room. A massive console blossomed there like a ten-foot tall, upside down steel flower. The Doctor, inside the bell-like structure covering the console, danced a graceful yet somehow awkward dance around the console, setting the coordinates. Cass felt like the universe had pulled the metaphorical rug from under her feet.

So one Time Lord appeared to be on the side of all things just. What was next? Daleks were misunderstood, and harboured a secret desire to cuddle? Nah, not likely. The line had to be drawn somewhere. Cass needed to get away, needed to think. To readjust her worldview. Rose would be safe. Even if the fact that a human was their soulmate didn't mean much to most Time Lords, it obviously _did_ mean something to the Doctor and Rose. Cass slipped down one of the many blindingly white corridors.

The lights blinked at her, guiding her down a side hallway. Cass could take a hint. She followed, smiling softly to herself. Cass stepped into the room indicated, and Cass's jaw dropped for the second time that day. There were books everywhere. She was inside a library the size of a large planetoid.

Ohila stood, swearing violently, in the doorway of the red stone building that had stood since the Dark Times, unspoken testimony to the Pythia's power. Thanks to that meddling fool Rassilon, the stone was crumbling, and the power once great enough change even anchor points of the Web of Time now dwindled down to only a trickle. Still, it was enough to change the universe, if you picked the right point.

The deaths of Bad Wolf and the Walker of Worlds was definitely the right place to start. The Oncoming Storm would be distraught over the death of his soulmate and her best friend, and would be easy to force into a regeneration. But she hadn't counted on the sisterly love the two humans harboured for each other.

Finally running out of breath(if not swear words), Ohila watched as the empty spaceship streaked across the upper atmosphere, and exploded into a pile of rubble not two hundred yards away. Ohila drew in a deep breath, filling her lungs and respiratory bypass… and promptly began to swear with renewed vigour.

The Doctor watched Rose as he piloted the TARDIS into the vortex. She was staring around in wonder, so the Doctor decided to really impress her. With a final flourish, he flipped the switch that made the ceiling transparent. The Doctor walked over to where Rose leaned, craning her neck, and leaned up against the support across from her.

Rose dropped her gaze from the spectacular vista revealed by the ceiling, and locked eyes with the Doctor. The silence dragged on. "Nice to finally meet you after all this time," Rose said, the statement coming out a tad flippant.

The Doctor's serene expression cracked like thin ice, turning into a wry grin. "Trust me, it has been considerably longer than you would expect."

Curiosity got the better of Rose. "Try me."

"Most Time Lords find their soulmates around two hundred fifty, give or take a few years. I am still fairly young for a Time Lord, at two thousand and change."

Rose's heart fluttered at the slightly self deprecating grin he wore. Rose whistled. "Impressive."

The Doctor dipped his head slightly. "At least you didn't insult my age."

He gestured all around them, indicating the hallways. "An entire dimension. Where would you go first?"

Rose pursed her lips thoughtfully, pointing at first one corridor, then another. "There. No, there."

Mind apparently made up, Rose dashed for the hallway she'd indicated.

 _Wait for me!_ The Doctor called mentally along the link he had with Rose. Then, laughing, he ran after her. The Doctor couldn't remember the last time he'd laughed, _really_ laughed.

Cass lay sprawled over an oversized bean bag, her bandolier and cargo belt hung neatly on a nearby chair. She stared up at the ceiling, some thirty feet above her. She didn't see it. Out of the frying pan and into the fire, Cass thought wryly. At this point, she was almost entirely certain that the Doctor was trustworthy. Cass's instincts almost never lied. It was the gift of someone who saw Threads. One type of sight bled into another, her aunt always said. But was it true what her aunt said?

" _Remember, Cass, the Time Lords are the reason your parents are dead. If they had smacked the Daleks down hard, then your mum and dad would be alive right now."_

The same lesson, drilled in over and over again. The question is, was she right?

There was just something about Rose. Not naïveté, nor weakness. No, the word was kindness. Despite living in the middle of a fully fledged Time War, the universe still hadn't managed to beat the compassion out of her.

The Doctor wondered what a monster like him, with gun-steel in his bones, trailing bloodshed, did to deserve someone like her. Even the Rani had a soulmate as icy and calculating as her. Rose looked at him oddly, and kicked a pine cone off the branch they sitting on. It whistled through ten feet of empty air, then hit the grass with a soft thud. "Whatcha thinking about?"

The Doctor caught her eye, smiling softly. "Just wondering what I've done to deserve you."

Rose grinned at him. "Nothing too heinous, I hope."

He laughed. Rose's gaze dropped to his lips. That was when the atmosphere shifted. Electricity zinged through him, mixing with the anticipation flowing through the bond. Rose began to close the distance, then stopped. "Can I kiss you?"

"Actually, I believe the question is 'may I-" She pressed her lips to his in a tentative caress, a whisper of amused exasperation rippling across the bond. It was a pleasant feeling, those emotions, and the Doctor wished that he could stay in this moment, or moments like it, forever. However, it was highly unlikely that any of them would survive long, not with a war of these proportions. Rose pulled back with a sigh, and a small, content smile. Then, as if remembering past transgressions, Rose lightly punched the Doctor in the arm.

It stung, but less than the Doctor was willing to admit. "Ow!"

Rose grinned at him. "For next time, don't be pedantic. It didn't work well for Cass."

The Doctor raised an eyebrow. "How so?"

Rose sank against the trunk of the tree, laughing. "She got in a few fistfights over it, then she tried it on my mother. I don't know what my mother did, but Cass never tried it again."

Rose yawned, a feeling of exhaustion quickly stifled washing over the link. The Doctor noted the circles under her eyes with concern and understanding. Fighting Daleks day in and day out didn't leave much time for sleep. Rose caught that thought, and frowned at him. _I'm fine._

There was an undercurrent of irritation to the thought. Her eyelids drooped momentarily, and Rose slid a little further down the tree trunk. Caught between amusement and alarm, the Doctor said, "The TARDIS will have your room prepared. Shall we go find Cass?"

Rose nodded, and for a moment the Doctor was worried that he would have to carry her down. But then Rose turned around and shimmied down the massive fir tree. The Doctor simply dropped the ten feet to the ground, landing lightly. He offered Rose a hand, feeling happier than he had in a while.

She smiled, and took it. They walked in companionable silence for a while, until Rose spoke up. Curiosity was on her face and in the bond. "I was meaning to ask. Just how many Time Lords have human soulmates? Can't be all that many."

The Doctor smiled slightly. "You might be surprised. Many renegades do, and so do a few Time Lords in good standing."

The Doctor began to tick numbers off on his fingers. "The Rani does, and that woman is just as cold hearted and vicious as her soulmate. The Master does, and so did Rassilon and Lady Flavia. My good friend Leela, who happens to be human, is bonded to Lady Romana."

They kept walking, and Rose gnawed on her bottom lip, mulling it over. She glanced over at him. "I know some Time Lords don't like humans. So if one ends up with a human soulmate, then why don't they just kill their soulmate?"

The Doctor cocked his head. He hadn't thought about it that way. "There is a very strong drive in humans and Time Lords to protect your soulmate and keep them happy. Hence, even without the First Law, domestic violence is almost unheard of. So is soulmate on soulmate murder. For Time Lords, it's partially because of those instincts, and partly because of the First Law."

Rose's honey brown eyes sparkled with curiosity. "What's the First Law?"

"Any Time Lord of Gallifrey who harms or kills their soulmate is put to death, with no chance of regeneration."

Rose's eyes widened. "Oh."

The TARDIS had apparently had enough of their nattering on, and placed the door to the library directly in front of them. The two of them stepped inside, startling Cass, who shot upright. Cass nearly dropped her copy of _The Star Beast_. Carefully closing the book's cracked pages, Cass stretched, glancing at the Doctor. "It's an interesting story, if a bit laissez faire on the details of space travel. When was it written, anyway?"

The Doctor grinned at her, relishing the thought of her reaction. "The 20th century. On Earth. So yes, they wouldn't have any idea of space travel excepting what I told them. Bobby was a nice fellow. I recall accidentally getting drunk, and giving him the concept of TARDISes. I still don't know how my drink got spiked with ginger."

Cass groaned, dropping her face into her hands. But the smile she got when the Doctor mentioned ginger was gleefully dangerous. Seeing that smile, the Doctor realised he had better get some dirt on Cass, and fast.

The Doctor hurriedly suggested, "Why don't we all head to bed? I'll show you to your room." But seeing Rose's too-innocent smile and Cass's sly grin, the Doctor knew he was going to be knee-deep in pranks before long.

The next morning dawned bright and early, or as bright as it could in the time vortex. Early was not optional, not living with Cass. Cass was a morning person, Rose most assuredly was _not_. By the time Rose blinked open her eyes, groaning, Cass was already dressed and zipping around.

Cass had kept her bandolier and cargo belt, as had Rose. However, Cass was choosing to wear her bandolier and belt over a denim jacket, a lilac shirt, and blue jeans. Quite incongruous. Rose dragged herself out of bed, quietly swearing at Cass using a few adjectives picked up during her time on the seedy little spacecraft.

Cass just laughed, heading out the door. Rose got dressed, and stood in front of the mirror, studying the result. With the bandolier, belt, and blue leather jacket over blue jeans, something seemed different. Rose studied her face, and realised her eyes were older, her face harder. She looked like the Doctor.

Fifteen minutes later, Rose found the kitchen. Cass was at the table, reading another book. The Doctor stood at the stove, flipping pancakes and humming a haunting melody that sounded like wind chimes. He looked up as she entered, smiling at her in a way that put an silly smile on her face and a swooping sensation in her stomach.

Rose sat down at the table, and waited. In due time, and Doctor turned off the stove, and started putting pancakes and syrup on plates. Somehow managing to balance all three plates, the Doctor sat down, pushing a plate towards each of the women.

Cutting into his pancakes, the Doctor asked, "If you could go to any place and time within the time lock, where would you go?"

Rose spoke first, feeling slightly choked up. "My dad. I'd go visit my dad."


End file.
